that's the trouble, Smiley and Jeannine, i don't know how, I've got a black hamburg, Jeannine, and another one someone gave me, no idea what it is..
anyway, our local garden centre has a sale on, I had to look, didn't I..we got two new ones, 2 years old for 99p each :o
thanks anyway, maybe someone'll come and tell us all how to do it, in fact, I'll start a thread :)